There are a variety of apparatus available for styling hair. One form of apparatus is known as a straightener which employs plates that are heatable. To style, hair is clamped between the plates and heated above a transition temperature where it becomes mouldable. Depending on the type, thickness, condition and quantity of hair, the transition temperature may be in the range of 160-200° C. A hair styling apparatus can be employed to straighten, curl and/or crimp hair.
A hair styling apparatus for straightening hair is commonly referred to as a “straightening iron” or “hair straightener”. FIG. 1 depicts an example of a typical hair straightener 1. The hair straightener 1 includes a first and second arms 4a, 4b each comprising a heatable plate 6a, 6b coupled to heaters (not shown) in thermal contact with the heatable plates. The heatable plates are substantially flat and are arranged on the inside surfaces of the arms in an opposing formation.
To use the styling apparatus to straighten hair, a squeezing force is applied to the arms so that they rotate about pivot 2 to clamp hair between the hot heatable plates. The hair is then pulled under tension through the plates so as to mould it into a straightened form. The hair straightener may also be used to curl hair by rotating the hair straightener 180° towards the head prior to pulling the hair through the hot heatable plates.
To power and control the heatable plates of FIG. 1, a mains power cable 8 is connected to a mains plug 10 to power the hair styling apparatus. Encased in the housing of the hair styling apparatus is a power supply circuit to convert the AC mains input to the appropriate drive voltage and a control circuit to control operation of the heaters and sense the temperature.
The fact that many electrical components are present in the hair styling apparatus means that the apparatus may become heavy to hold for an extended period of time. Furthermore design freedom can also be limited as component sizing imposes limitations on the shape and size of the hair styling apparatus. This invention seeks to address such issues by developing improvements to the power supply and control systems for such hair styling appliances.